In the art of building construction it is common practice to cast the base or foundation with concrete. A trench or excavation channel is prepared into which the forms, either made from steel or wood, are set up adjacent and connected to each other matching the dimensions of the required foundation (footing). The forms, which are steel panels or wooden boards or planks, are put into position on their edges across from each other and parallel to each other near the side walls of the trench.
The materials that are commonly used for concrete forms are easily damaged. If steel forms are dented or bent, they are essentially useless. Wood forms are difficult if not impossible to use over and over again. Moreover, wood is a precious resource, and thus undesirable for use as a disposable form material.
After being placed into position, the forms are usually secured by stakes and other devices that are sufficient to prevent the form from being displaced. As more and more governments update their respective building codes, the number of locations that require pier blocks to be reinforced with steel is growing. Steel reinforcement generally takes the form of reinforcing bars (re-bar) that is placed in the form in such a manner that the wet concrete completely covers the reinforcing bar. Horizontally oriented reinforcing bar is generally held in place by using separate reinforcing bar mounting stands. Some of the generally available reinforcing bar stands can be connected to the form after the form has been constructed, while others are positioned in the form and the reinforcing bar is placed on the device. Vertically oriented reinforcing bar is generally secured in the form by devices that are connected to the form after it is constructed. Placing the reinforcing bar securing devices in the desired location within the form requires additional labor and some degree of skill.
After the forms are completely assembled and the reinforcing bar has been secured, concrete is poured within the forms and allowed to set and cure. Typically, when the concrete has hardened, the form is removed by a process that is labor intensive, and generally requires as much physical labor and cost as the initial set up. Additionally, concrete can stick to the forming faces of wood, steel and other materials to the point where adequate cleaning is impossible. Release from the concrete once it has set usually requires the use of a release agent or labor-intensive scraping which complicates the construction process.
In addition to the problems noted above, the concrete forms that are generally used for foundation footings can be difficult to handle because of their weight and bulk. These heavy bulky forms generally require at least a medium sized truck to move enough material to create a form for a single-family dwelling. Once the foundation has been completed, the truck must be used again to transport the form to the next job site. The forms must be stored when they are not used for extensive periods of time, which requires significant space. These problems and others add time and costs to foundation construction, which increases the purchase price paid for a newly constructed building by consumers.
A number of inventions have attempted to address the problems associated with conventional foundation footing forms. U.S. Pat. No. 5,399,050, issued to Jacobus discloses thermoplastic side walls that can be connected with bars to create a form with integrated drainage tiles. The form is left in place after the concrete has cured. The Jacobus patent does disclose a device that reduces labor costs by leaving it in place after the concrete has cured, but it still must be assembled on the construction site by connecting the two side walls together. The Jacobus patent does not address the fact that the pre-made side walls may be too long in some instances and may be difficult to cut to the correct size. Additionally, the Jacobus patent does not address the placement of vertical and horizontal reinforcing bar in the form, nor does it provide any means for securing such reinforcing bar in the form.
U.S. Pat. No. 5,475,950, issued to Palmer, discloses a lightweight permanent concrete footing form having a horizontal base with two side walls extending upwardly therefrom. The form disclosed in the Palmer patent also has ducts for draining water away from the completed footing. As with the Jacobus Patent, the disclosure of the Palmer patent does not address how the plastic form can be cut to size, nor does it address reinforcing bar placement or securing the reinforcing bar in the form. Additionally, the devices disclosed in both the Jacobus and Palmer patents include integral drainage conduits and this could make the devices bulky such that they would require significant storage space prior to use and at least a medium sized truck for transportation to the job site.
Thus a need exists for forms for concrete foundation footings that are not made from wood or metal so that these resources can be preserved. Such forms should be lightweight and easily installed by a minimum number of laborers. A need also exists for such forms that would provide integral devices for placing and securing both vertically and horizontally oriented reinforcing bar in the form. Such forms that are, collapsible, easily stored and easily transported would be significant improvements over the prior art.